A karabiner is an oval or D-shaped coupling link with a closure and is an essential piece of equipment when rock climbing and mountaineering. Existing karabiner designs rely on a spring biased gate and it is this gate which is the main weakness of the karabiner. In particular, the gate can open due to the rope pressing on the gate, or when the karabiner is subjected to a sudden shock. Since the strength and safety of the karabiner is adversely affected when the gate is open, karabiners having a locking mechanism in the form of a screw-gate or bayonet fitting are available for use when safety is critical to protect against accidental opening of the karabiner gate. However, these karabiners are much more expensive, harder to use, heavier and can still open during routine use. Furthermore, karabiners in general are designed to be structurally loaded only along their major axis and are much weaker if cross-loaded, loaded in more than two directions, or loaded over a sharp edge, and ultimately may fail under these conditions.